Got problem with money appears

[tysanio]

Got this error ERROR: "systemforfaction line 800": attempt to compare number with nil

        local mostRecentWeek = 0 
        local currentWeek = 0 
        if query then 
            while true do 
                row = mysql:fetch_assoc(query) 
                if not row then break end 
                 
                local id = tonumber(row["id"]) 
                local amount = tonumber(row["amount"]) 
                local time = row["newtime"] 
                local week = tonumber(row["week"]) 
                currentWeek = tonumber(row["currentWeek"]) 
                [i]this line[/i][b]if (week) > mostRecentWeek then mostRecentWeek = week end 
[/b]                if not transactions[week] then transactions[week] = {} end 
                local type = tonumber(row["type"]) 
                local reason = row["reason"] 
                if reason == mysql_null() then 
                    reason = "" 
                end 
                 
                local from, to = "-", "-" 
                if row["characterfrom"] ~= mysql_null() then 
                    from = row["characterfrom"]:gsub("_", " ") 
                elseif tonumber(row["from"]) then 
                    num = tonumber(row["from"])  
                    if num < 0 then 
                        from = getTeamName(exports.pool:getElement("team", -num)) or "-" 
                    elseif num == 0 and ( type == 6 or type == 7 ) then 
                        from = "Government" 
                    end 
                end 
                if row["characterto"] ~= mysql_null() then 
                    to = row["characterto"]:gsub("_", " ") 
                elseif tonumber(row["to"]) and tonumber(row["to"]) < 0 then 
                    to = getTeamName(exports.pool:getElement("team", -tonumber(row["to"]))) 
                end 
                 
                if tostring(row["from"]) == tostring(-factionID) and amount > 0 then 
                    amount = amount - amount - amount 
                end 
  
                table.insert(transactions[week], { id = id, amount = amount, time = time, type = type, from = from, to = to, reason = reason, week = week }) 
                --outputDebugString("transactions["..tostring(week).."]="..tostring(#transactions[week])) 
            end 

I dont know what wrong i'm new to Scripting lua i just pickup ressource and look how its work.

[Enargy,]

I dont know what wrong i'm new to Scripting lua i just pickup ressource and look how its work.

start with something easier than this, not what difficult as MySQL, SQL, tables

[tysanio]

Well i start with difficult thing to do after it easy for me ^^